Starter for small internalcombustion engines



Jan. 13, 1953 R. s. DEMITZ 2,625,143

STARTER FOR SMALL INTERNAL-COMBUSTION ENGINES Filed May 9, 1947 Illlb.

FIG

FIG 2 Patented Jan. 13, 1953 UNITED STATES PATENT OFFICE STARTER FOR SMALL INTERNAL- COMBUSTION ENGINES Roberts S. Demitz, Fort Knox, Ky.

Application May 9, 1947, Serial No. 747,158

1 Claim. 1

The invention relates to the securing of rotary motion for starting by manually pulling a rope wound around a shaft, which imparts a starting effort and at the same time winds up a set of rubber strands, which in turn enables the operator to allow his starting rope to rewind itself on said shaft and thus ready the machine for anew starting effort with no delay; the objectives of the invention are, first, to provide an effective, light, cheap starter available to all model enthusiasts who use small (155 cubic inch displacement or less) interna1 combustion engines; to embody manual operation in the said starter in order to avoid costly maintenance 'of' some other source of power; to insure quick readiness for each successive starting effort in spite of the manual source of power by employing a simple re-winder for the starting rope, in the form of a simple rubber strand energy storing principle in which the starting effort itself winds "up rubber strands in addition to spinning the engine to be started, and which re-winds the starting rope as quickly as the operator desires to feed the same back onto the starter shaft; to utilize, for purposes of quick attachment to, and release from, the starter, (of the engine to be started) only such simple attaching or power linking devices as the cone and dog type of clutch, said clutch to be fabricated (driving member) of simple and easily procured rubber-impregnated fabric tube, in turn rendering the machine universally adaptable to all styles of propeller securing devices, all propeller spinners, and propellers of one, two, three and four blades, with-out extra cost; generally, to aid the model sport and hobby as a whole by removing the need for slow, tedious, and often dangerous finger cranking of the aforesaid engines, this to be done at low cost to the individual.

One form of the invention is illustrated in the accompanying drawing, in which Figure l is a side View of the complete machine; Figure 2 is a top view of the machine with the rubber strands ll removed, as well as the link It), rope l5, collar 8, and hub 1, for purposes of added clarity; Figure 3 shows the front view of the machine, e. g., the end from which energy for starting engines is taken; Figure 4 constitutes an enlargement of the shaft 3, hub I, and collar 8 view, as in Figure 1, except that a simple cone clutch type of collar, as was the case in Figure 1, has been replaced by a dog clutch type of collar (one dog, only being used) in order to illustrate that type of clutch (used when the propeller has not been fitted with a spinner); Figure constitutes a 2 front view of parts shown in Figure 4, at the same scale.

The base 1 and the tool compartment 2 (fitted with covers H and 18., one of which is a hinged door, and the other of which is a firmly fastened cover) constitute the basic frame-work of the machine. A shaft 3 uses for bearings the simple drilled metal straps 4. These straps are screwed to the wood toolbox 2 as indicated. The shaft is kept from .slidinglongitudinally (but allowed to rotatefreely) 'bythe drilled metal discs 5 and hub '1. The discs '5 and hub 1 are secured to shaft '3 by theset-screws 6 (discs 5 are identical).

A collar 8, of rubber impregnated fabric (similar to automotive water-hose used in cooling systems) is secured to the hub 1 'by mean-s of rubber cement, the collar 8 being a tight fit over hub 1 in order to secure acheap and lasting bond.

The collar 8, shown sectionalized by a vertical, centerline plane in Figure 1, constitutes the female member of a cone type clutch. The propeller spinner B of the portion of a model aircraft reproduced in Figure 1, constitutes the male member of the clutch assembly. The collar 8, rotating with shaft 3 and collar I, will rotate the spinner 9 (and with it the engine that is to be started) as long as collar 8 and spinner 9 are engaged. When the starting impulse is ended the spinner i9 is removed from collar 8 and the machine is rewound-for another effort.

Theshaft 3 is drilled "and provided with a wire link I0, through which several heavy rubber strands H are passed. The other end of the said rubber strands are held by a hook l2, which is anchored in the uprightv l3. Upright 13 is in turn secured at its bottom end to base I by countersunk screws, and braced thereto by .metal strap 1.4.

Asmall diameter .rope [5 (of durable quality) is secured to either disc .5 by means -:of having one end of th rope passed through the hole provided in the discs, and knotted as indicated in Figure 1. The rope is wound around shaft 3 (50-75 turns) on that portion of the shaft lying between the discs 5. The assembly of the shaft 3 and discs 5 and rope l5 now constitutes a spoollike arrangement, the spool containing 50-15 turns of rope.

The machine is operated by having the operator place one foot firmly in place at general location IS in Figure 2, and also grasp the end of the rope I 5 in one hand. The spinner and/or propeller assembly of the engine to be started is insorted into part 8 (collar). In doing this, the operator may hold the starting rope 15 in one hand and the model airplane (or etc.) in the other, holding the spinner and/or propeller assembly into the rotating part 8 (collar) as he pulls on the starting rope I5, and removing the spinner and/or propeller assembly while he allows the rope to be rewound. This system will work splendidly for engines up to the .50 cubic inch displacement type; however, it will be found less tiring, in the case of the very high output competition type engines of .59 cubic inch and larger, to have an assistant assume the task either of holding the model or working the starter. This is common practice with the cumbersome and expensive homemade storage battery and electric motor type of starter now in use.

The steady pull exerted on rope l5 will give 50-75 very rapid revolutions to the engine to be started. A peak of about 3000 R. P. M. may be reached, if desired, which assures easy starting of the balky or the most worn out of engines. The spinner and/ or propeller assembly is removed from contact with the collar 8 as soon as steady firing of the engine is heard. This will ordinarily be found to occur in the midst of the second starting effort following priming of the engine.

The 50-75 revolutions imparted to the shaft 3 (and hub 1, etc.) cause the rubber strands II to store the same number of revolutions in the form of energy which attempts to rewind the machine for another attempt at starting. The operator controls this energy, using it to rewind his starting rope in neat coils on the shaft 3. The rewinding process is accomplished in a matter of a few seconds.

Figures 4 and 5 are shown in order to illustrate the simple collar 8, as shown in Figure 1, after it has been modified, by an ordinary penknife or razor blade, into the dog clutch type. In this case, where the model engine has no substantial spinner, the user simply cuts down his collar 8 until it contains a dog similar to that shown in Figures 4 and 5, and regulates (by means of setscrews) the relationship of the collar 8, hub I, and shaft 3, until he may press the propeller against collar 8 and at the same time find that the nut which holds the propeller to the motor shaft will slip into the hole in hub l (which was bored to receive shaft 3). The starting process will then be as described heretofore, with the dog preventing slippage (or complete absence of rotation), and with the model engine held centered to the starting machine by virtue ofthe insertion of the engine propeller nut into the center hole of hub l. The principle of employment of only one dog is important, inasmuch as this type will fit a propeller of any number of blades up to four blades, the maximum normally used in model building.

I am aware that, prior to my invention of the machine that I have described. above, starting devices for internal combustion engines have existed wherein pull cords were used in conjunction with pulleys and similar members such as drums, in order to produce rotating starting energy which was eventually transferred to the engine to be started by means of a shaft; that restoring springs and similar devices have been used in order to rewind such cords upon such pulleys or drums in a semi-automatic fashion, at the will of the operator; that electrically powered, spring powered, and flywheel-inertia powered types of portable starters have been used in the starting of the small model engines that I have referred to above. I do not claim such combinations broadly. Further, all of the arts of record which may be considered to apply in the case describe less simple machines which inherently depend upon the use of pulleys, grooved operating members (or drums, the equivalent) in conjunction with and in addition to a basic shaft or a combination of shafts; it can be seen that, by my invention, I have been able to eliminate, in a successful starter, all significant moving parts other than the single basic shaft proper, which shaft is actuated directly, by actual contact, by the pull cord during the starting effort, and again actuated directly by direct contact by an elastic during the period when the operator permits the machine to rewind itself. Specifically, I claim:

A portable starter for small internal combustion engines comprising a frame, said frame having an extension provided with an outrigger, a shaft supported near each of its ends by bearings affixed to the upper portion of one end of said frame, a hollow cylindrical member secured to one end of the said shaft, a pull-cord wound directly upon and around the said shaft with one cord end fastened to the shaft, an elastic strand fastened to the other end of the shaft in extension of the shaft axis and further secured at its other end to the said outrigger, whereby the hub of a model airplane or boat propeller, or of a race car wheel, may be inserted into the hollow cylindrical member to receive successive starting impulses of manual origin.

ROBERTS S. DEMITZ.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 911,538 Eichenfels Feb. 2, 1909 1,178,162 Lauchin Apr. 4, 1916 2,338,929 Goiot Jan. 11, 1944 2,385,963 Beard Oct. 2, 1945 2,391,141 Dour et a1 Dec. 18, 1945 2,475,750 McCormick et a1. July 12, 1949 FOREIGN PATENTS Number Country Date 852,228 France Oct. 23, 1939 

